Water from Air

Saw a very cool water generation system that works by “stealing fog” — condensing water out of the air using a really low tech method… Click the picture to jump to their site:

I was thinking about this last year using something based on redwood trees, but their idea is much more elegant (and obviously more than just words).

I wonder though — how much water can you safely pull out of the air before you start affecting the local climate? After all, we've certainly managed to pull enough water out of the ground to do significant environtal damage to our aquifers and other groundwater resources… can we “dry out” the air by stealing too much fog and converting it into contaminated sludge that can't re-enter the system?